Saturday, October 10, 2009

The October constellations are a mixed bag. At sunset, the summer constellations glow in the west, but are outshone by the winter constellations after midnight. So just when you thought summer was finally behind us, these stars tell you: no, not quite yet. On the bright side, a lot of the constellations have vaguely Star Wars-esque names, so if you're a Lucas fan, this is the month to check them out.

The Great Square, a constellation within Pegasus, will replace the Summer Triangle as the most prominent night constellation. Watch out for the distinctive W-shape of Cassiopeia in the north, and also Perseus nearby. The Andromeda Galaxy is very noticeable as a large bright elongated smudge, even through binoculars. If you have a telescope, you can catch sight of dust lanes in our nearest galactic neighbour (see star map). If you have binoculars, check out the rather stiffly named star cluster, M-15 (what did I tell you about Star Wars?). Don't worry: they're far more interesting than they sound.

After midnight, look out for the bright star Capella in the constellation Auriga. Right beside it, you'll see a large, smudgy patch. This is M45, the Pleiades, in the constellation. In the same constellation is Aldebaran, a bright orange star. If by this time you still have the energy for more stars, check out Orion (the hunter) in the southeast. Orion is easily one of the more distinctive constellations, with a belt formed by three stars set within the giant silhouette of a hunter.

Planet observing:You'll have a great chance to see Mercury, that elusive little planet, in the eastern skies just before sunrise when it will be a little left of a brilliant Venus. Venus will be so brilliant you can pick it out fairly late into the morning.

Mars, in Gemini, is rising in the northeast well before midnight, and by dawn it will be climbing high into the southern sky.

Jupiter, in Capricornus, will be brighter than most stars and will set in the southwest around midnight.

Saturn, which was hidden behind the sun for a large part of September, will emerge in the dawn sky to the lower left of Venus, though it'll be considerably dimmer than other planets and stars. It'll be right beside Venus on 13 October.

If you tire of planets, the Orionid shower will be visible during the second half of October and will last for about a week or more. The best time to see these showers is early in the morning when moonlight won't blot them out. There will also be sporadic showers from other systems throughout the night.

Click on http://apod.nasa.gov/apod/archivepix.html if you fancy vivid pictures of galaxies and other deep sky objects. These pictures were taken by NASA's newly repaired Hubble Space Telescope and are really terrific.